Efren Carrillo served two terms on the Sonoma County Board of Supervisors, having been first elected in 2008 at the age of 27. While on the board he was a key leader for the establishment of Sonoma Clean Power. He also worked at the USEPA, Sonoma County Economic Development Board, Sonoma County Business Environmental Alliance, for Assemblyman Joe Nation, and for Redwood Credit Union. He has a degree from UCB in environmental science and policy.